umount

Usage: umount [OPTION]... DEVICE|DIRECTORY

Options:

			-a	Unmount all file systems
			-r	Try to remount devices as read-only if mount is busy
			-f	Force filesystem umount (i.e., unreachable NFS server)
			-l	Do not free loop device (if a loop device has been used)
		

Example:

			$ umount /dev/hdc1